1. Field of the Invention
The present invention relates to gate valves, and more particularly, to a gate valve with secure sealing mechanism.
2. Description of the Related Art
U.S. Pat. No. 7,341,237 discloses a valve mechanism for optionally sealing or opening a valve opening in a casing, while the valve opening is provided with a seat surface. Therein, the valve mechanism comprises at least a valve member capable of moving in parallel or vertical to the seat surface of the valve opening in the casing. A driving board is disposed in the casing and connected to at least a valve member, wherein the driving board is able to move horizontally, such that the valve member is driven to move horizontally.
The valve mechanism aforementioned is able to drive the valve member to move horizontally or vertically by use of the driving board, thereby sealing the valve opening. However, the valve mechanism is not provided with any locking devices or secure mechanisms for stably securing the valve member at the sealing position, such that the driving board is easily shifted or displaced. As a result, the valve member is hindered from effectively sealing the valve opening. In a more serious environment, fluid tends to be leak out from the valve opening, causing unnecessary loss.